Vdt - control tone cadence reporting, Syntax, Defined values – Comtrol AT Commands User Manual
Page 199: Reporting current or selected values, Reporting supported range of parameter values, Result codes

AT Commands for CX81801/CX06833/CX81300/CX06827 Modems Reference Manual
102184B
Conexant
5-23
5.2.3
Speakerphone Commands
+VSP - Speakerphone ON/OFF
This command turns the speakerphone ON or OFF
Syntax
+VSP=
Defined Values
Decimal number corresponding to the selected option.
0
The speakerphone function is OFF. (Default.)
1
The speakerphone function is ON.
Reporting Current or Selected Values
Command: +VSP?
Response:
Example:
0
For the default setting.
Reporting Supported Range of Parameter Values
Command: +VSP=?
Response: (
range)
Example: (0,1)
Result Codes
OK
ERROR
Otherwise, or if not in Voice Mode.